The effect of posture in premature infants on the arterial oxygen saturation, fraction of inspired oxygen and abdominal distension

Background: Putting infants in a posture that reduces oxygen requirement and the complications of the continuous positive airway pressure method is very important. This study aimed at examining the effect of the posture on the arterial oxygen saturation, fraction of inspired oxygen (FIO2) and abdominal distension in premature infants with the respiratory distress syndrome under nasal continuous positive airway pressure. Materials and Methods: In this clinical trial study, 41 premature infants were selected by the simple random sampling and one-group before-after design. The amounts of arterial oxygen saturation, FIO2 and abdominal distension in supine and prone positions were recorded in a data-collection form. Results: There was a significant difference between the mean FIO2 and between the mean abdominal circumference in the prone and supine positions (P=0.022, P<0.001, respectively). There was no significant difference in the mean of arterial oxygen saturation between the two positions (P=0.749). Conclusion: According to the results of the present study, the neonates’ abdominal distension and FIO2 decreased in the prone position. Thus, this supportive, free of charge and effective method can be recommended for these neonates

Constrained pre-equalization accounting for multi-path fading emulated using large RC networks: applications to wireless and photonics communications

Multi-path propagation is modelled assuming a multi-layer RC network with randomly allocated resistors and capacitors to represent the transmission medium. Due to frequency-selective attenuation, the waveforms associated with each propagation path incur path-dependent distortion. A pre-equalization procedure that takes into account the capabilities of the transmission source as well as the transmission properties of the medium is developed. The problem is cast within a Mixed Integer Linear Programming optimization framework that uses the developed nominal RC network model, with the excitation waveform customized to optimize signal fidelity from the transmitter to the receiver. The objective is to match a Gaussian pulse input accounting for frequency regions where there would be pronounced fading. Simulations are carried out with different network realizations in order to evaluate the sensitivity of the solution with respect to changes in the transmission medium mimicking the multi-path propagation. The proposed approach is of relevance where equalization techniques are difficult to implement. Applications are discussed within the context of emergent communication modalities across the EM spectrum such as light percolation as well as emergent indoor communications assuming various modulation protocols or UWB schemes as well as within the context of space division multiplexing

Ethnic mobilization among Korean dry-cleaners

Korean immigrants in the U.S. rely heavily on ethnic resources to start small businesses.  Ethnic resources include business networks and knowledge, start-up capital, and access to labor power that are embedded in networks of family, friends, and co-ethnics.  This paper shows how Korean dry cleaners in Southern California used ethnic resources to mobilize in response to an environmental policy initiated by the South Coast Air Quality Management District (AQMD).  While Korean immigrants used ethnic resources to start dry cleaning businesses, they found themselves working with a toxic chemical.  In 2002, AQMD required dry cleaners in Southern California to convert to costly alternative machines by 2020.  Korean dry cleaners used ethnic-based collective action, particularly the Korean Dry Cleaning Association, as a means of fighting for regulatory concessions.  They also used ethnic resources to overcome cultural and linguistic barriers to facilitate the adoption of alternative cleaning machines in compliance with the regulation.   &nbsp

Production and Some Characteristics of Bulk Nanofibers Layers by Manipulation of Electrospinning System

The main purpose of this study is to introduce a new method for nanofibers by bulk layer production. In the present method the effect of some parameters including take-up velocity, applied voltage, polymer solution concentration on density of produced layers is investigated. The compression characteristic of nanofiber layers produced under optimum electrospinning is also investigated. It was shown that the layer density decreased by increasing polymer solution density while an increase in applied voltage and take-up velocity increased layer density. The lightest layer with density of 0.000374215 g/cm3 with 99/98% porosity are produced by this method at 15% polymer solution concentration with take-up velocity equal to 4.24 m/min and 8 kV voltages

Alignment of Electrospun Nanofibers and Prediction of Electrospinning Linear Speed Using a Rotating Jet

Anew and effective electrospinning method has been developed for producing aligned polymer nanofibers. The conventional electrospinning technique has been modified to fabricate nanofibers as uniaxially aligned array. The key to the success of this technique is the creation of a rotating jet by using a cylindrical collector in which the needle tip is located at its center. The unique advantage of this method among the current methods is the ability of apparatus to weave continuously nanofibers in uniaxially aligned form. Fibers produced by this method are well-aligned, with several meters in length, and can be spread over a large area. We have employed a voltage range of (6-16 kV), a collector diameter in the range of 20-50 cm and various concentrations of PAN solutions ranging from 15 wt% to 19 wt %. The electrospun nanofibers could be conveniently formed onto the surface of any thin substrate such as glass sampling plate for subsequent treatments and other applications. Therefore, the linear speed of electrospinning process is determined experimentally as a function of cylindrical collector diameter, polymer concentration and field potential  difference